Field of the invention
This invention relates to internal combustion engines and specifically concerns apparatus for use in connection therewith for treating the exhaust gas delivered from the engine when in operation.
The invention has been developed primarily for treating the exhaust gas of internal combustion engines used in locomotives or otherwise in underground mine workings in which the composition of the atmosphere gives rise to a fire or explosion hazard. Regulations governing the use of internal combustion engines in such underground mine workings require that the engine and its exhaust system shall have complied with an officially approved specification governing inter alia:
(a) the maximum surface temperature of the engine and exhaust system thereof, PA1 (b) the temperature of the exhaust gases emergent from the exhaust system into the atmosphere, PA1 (c) the composition of the exhaust gases so emergent.
It is, however, to be understood that the invention may be applied to apparatus for treatment of the exhaust gas of internal combustion engines used in environments in which similar or analogous hazardous conditions arise, either less severe or more severe than those encountered in underground mine workings.
In apparatus of the character specified one of the problems which arises is control over the composition of the exhaust gas emergent into the atmosphere, and to exercise such control the apparatus usually includes a conditioner chamber containing a liquid (normally water) through which the exhaust gas is passed to dissolve or otherwise absorb noxious constituents. In apparatus of conventional design, however, the temperature at which the gas enters the conditioner chamber is often relatively high, e.g. 200.degree. C or more and this leads to significant vaporization of the water contained in the chamber, and such water in the form of vapor may be entrained in the flow path of the exhaust gas leaving the conditioner chamber so that the volume of water contained therein is gradually reduced.
In underground mine workings it may be inconvenient, or even impossible, to return the locomotive to a service area or station in the underground working at frequent intervals to enable water to be added to the conditioner chamber, yet a hazardous condition may arise if the water level is allowed to fall too low.